Electrically-controlled carburetor



Am-i116, 1929.. H. s. PARDEE 1,709,628

ELECTRICALLY CONTROLLED CARBURETOR Filed April 6. 1922 a sneezs sneet 1 A ril 16, 1929. H. s. PARDEE 1, 0

ELECTRICALLY CONTROLLED cAnmma'ron Filed April 1922 3 Sheets-Shoot 2 April 16, 1929. H. s. PARDEE ELECTRICALLY CONTROLL BD CARBURBTOR s Sheds-Sheet 3 Filed April 6. 1922 Vllll Patented Apr. 16 1929.

; UNITEDFSTATES. PA-rENT:" oFm -1- HARVEY s. manna, or CHICAGO, runvorsns'srenonro BELLE EVANS manna, or

RAVINIA, rumors. r

ELECTRICALLY-CONTROLLED. A:aeunrnzon.

Application filed April 6, 1922. Serial No. 550,243.

' This inventionrelates to a mixing device,

throttle, and solenoid, separately and in conjunction with one another. e

Among the several objects of the invention may be noted the provision ofa simple and insame time sensitive to slight changes in the current through it; and the provision of a solenoid-controlled mixing and throttle device having some or all of the above features and acting in conjunction with a suitable source of power, such as an engine-driven generator, to maintain withinnarrow limits the desired characteristic of the system. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists offthe elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structure hereinafter describedand the scope of the application of which will befindicated. in the following claims. 7 f

In the accompanying drawings, in which is shown one of various possible embodiments of the invention,

Fig. 1 is a section showing the solenoid with mixing device and throttle open; I

. Fig. 2 is a similar view showing the parts in closed, or substantially closed, posit-ion;

Fig. 3 is an elevation of Fig. 1, showing in addition a reservoir and pump associated therewith; v v I v r Fig. 4 is a plan of Fig. 3, with parts broken away;

Fig. 5 is an elevation of a throttlemember shown in Figs. land 2, showing the arrangement of ports therein; and

Fig.6 is a wiring diagram. 7

Similar reference characters indicate corre sponding parts throughout the several views of the drawings. a

Referring now more particularly to Fig.1 of the accompanying drawings, there is illustrated a main casting having an intake opening 2 for air, a delivery port 3 forthe m xture, a supply conduit 4 for the liquid fuel, such as gasoline, and an annular-memher 6 having a passage from the fuel inlet 4 to a 'jet 17. The member-6 is normally fixed in position; Surrounding the upper portion of the member 6, and movable with respect thereto, is the member 8 (shown in elevation in Fig. 5) having apertures forming the ports 9, andmovable either manually or by automaticmeans such as the solenoid 11 illustrated' in Figs. 1 and 2. .The solenoid construction is hereinafter described. The memher 8 in the present instance acts as a venturi (comprising thus a movable element for effooting, in cooperation with the part 6, constriction of the air passage) and also as the throttle.

The throttle valve as shown in Fig. 1 is open, and in Fig. Qis closed. By closed is meant a position in which the flowof fuel is substantially, but not necessarily completely,1shut off. By open is meant a position permitting a comparatively free flow of fuel, but not necessarily the position for maximum flow, as the device8 may have a strokeextending. upward beyondthe position illustrated in Fig. 1. V

In the closed position shown in Fig. 2, in which the member 8 is lowered, the most constricted portions 13 (Fig. 5) ofthe ports 9 are the only portionsof the ports-that permit communicationbetween the intake 19 and the delivery port'3.

Theliquid fuel flows outwardly through the narrow space 17, by suction, the restricted passage between the member 8 and thepart 20 of the member 6 acting as a venturi.

The throttle opening at theapertures 9 has i an area or section (crosswise of the flow. of air ormlxture) that varies with movement of the member 8. A1r 1s drawn inwardlyto the right through an air inlet Q'and down-- wardly through the annular space 19 between the members 6. and 8.

In Fig. 2, as indicated above, the member 8 is shown in closed position, with the ports 9 nearly cut oil'. The point where the fuel suction takes place, that is, the annular space between ports 20 and 8, is also reduced in area,

causing a compartively high velocity and conscquently an increased suction past the jet open ng.

As the member 8 moves upward from this Fig. 2 (closed) position the mixture is throttled to a progressively less extent (that is, the flow-is progressively increased) by the progressive increase of'the size of the ports 9 at the edge 10. In the construction of the present invention, the suction at the jet is, unlike a fixed-venturi construction, adjusted so as to give a constant ratio of air to fluid fuel under varying rates of flow. The throttling is done primarily at the edge 10 of the ports and not at the variable venturi. The venturi is for the purpose of furnishing and regulating the suction to draw the fuel.

With the present invention the mixture ratio is maintained at the desired value under widely varying load and speed conditions of the engine, since the proper ratio of suction to rate of flow of air is effected automatically for the various working positions of the member 8.

Adjustment of richness of mixture may be made by changing the setting of the needle valve 21, shown in Fig. 4. The needle valve ismounted in the path of the liquid fuel from the chamber 25 to the supply conduit 4, and may be of any suitable construction. Liquid fuel is supplied to the chamber 25 by means of a pump 62 adapted to draw liquid from a reservoir 64. An overflow pipe 66 in the chamber 25 limits the height of liquid therein. A preferred way of determining a suitable shape for the'ports 9 experimentally is to start the engine with ports that are at least large enough to deliver a sufficient quantity of mixture for full power when wide open. The needle valve is then adjusted so that power is delivered by the engine at maximum fuel etliciency when this member 8 is wide open. Then by successive adjustments inthe vertical positioning of the member 8 and by minor operations of cutting away the ports, with such further changes in the setting of the needle valve as may be needed, the proper shape of ports and relations of ports to edge 10 may be readily found for enabling maximum power or maximum engine efliciency to be obtained at all positions of the member 8, without changing the setting of the needle valve for varying load conditions. With certain hydrocarbons such as gasoline, the most efficient mixture is not widely different from the mixture that gives maximum power; so

that when the needle valve is so adjusted for any given setting of the venturi and throttle as to give maximum power, then the most efiicient mixture is approximately obtained. It is thus not ditficult to ascertain the proportioning of ports and position of the member 8 for approximately the best working conditions. The determination may be mademore exactly by measuring theair and fuel separately, if desired.

The member 8 may be moved vertically by any convenient controlling means. A preferred form of control is an electric solenoid, such assolenoid 11, illustrated in Figs. 1 and 2.

The solenoid may be controlled by a manually or automatically operated rheostat (not shown) or, in installations such as an enginedriven electric generating plant (Fig. 6) the solenoid may be connected in various ways, such as across the generator G (solid lines in Fig. 6) or to its work circuit L (dotted lines in Fig. 6) and thus move in accordance with variations in generator voltage or other variable factor. For example, if the solenoid is connected across the generator voltage (solid lines in Fig. 6), an increase in voltage causes increased magnetic effect in the solenoid, lowering the solenoid core 27 and moving the member 8 downward toward its closed position shown in Fig. 2, thereby decreasing the fuel supply to the engine and neutralizing or preventing the incipient in crease in voltage. Similarly, any tendency of the generator voltage to decrease is met by upward movement produced by a spring 43 and lever 44, of the solenoid core or element 27 and member 8, sufficientto restore or maintain the normal value of the voltage.

The solenoid per se preferably comprises a bobbin 29 on which the coils 31, 32 are wound, a shell 33 of magnetic material surrounding the coils and provided with an inwardly extending annular rib 35 at a point above the coils, this rib registering with the disc-shape flanged portion 37 of the core 2?, with a suitable air-gap 39 between rib and flange. The rib and flange are preferably in registry, that is, juxtaposed, when the core is at or near its uppermost position (Fig' 1), though this relation of rib and flange may be varied to meet varying service requirements, without departing from the spirit or scope of the present invention. 2 In the lowered position of the core (Fig. 2) the flange is shown as below the plane of the rib, causing the magnetic attraction between the two to tend to raise the core. This is in opposition to the downward pull caused by the lines of force passing from the core to the magnetic plug or stop 41. The increased air-gap between rib and flange also tends to weaken the downward pull onthe core.

A third factor affecting-the movement of the core is the spring 43, mounted, in this instance, on the casting'l and adapted to be flexed by a bell-crank 44' connected to an antifrictionpin 45 mounted in a vertically reciprocating extension 46 pinned as at 48 upon the upper end of the solenoid core 49. The extension 46 is in turn secured to the annular member 8 by means of the'pin 51 shown in Figs. 1 and 2. During the downward movement of the member8 and solenoid core from the open position shown in Fig. l to the closed position shown in Fig. 2, the spring 43 abuts successively against adjustable stops 53. This abutting of the spring against the successive stops varies the effective levera e ing upon what shape of curve is wanted in order to get the desired results. lnstances no spring at all is needed. lVith the core in its 'f per position shown In some U in Fig. 1, the downward movement is etlfect ed by the attraction on the core. As the core 1 moves downward, thisv attractionincreases.

At the same time the upward attraction between rib and flange opposes the downward pull on the core, and the weakening effect of the increasing airgap 39jtenr s to reduce the total magnetic flux below what it would otherwise be and therefore likewise the downward pull.

A guide 47 may be provided to keep the core in a central position with respect to the bobbin. v

The apparatus of Fig. 1 is preferably'so proportioned that the moving parts are always in stable equilibrium throughout the working stroke, with no tendency to move in either direction save as required by'changing strength of the current in the solenoid coils. By working stroke is meant the normal travel during the operation of the parts 27, 37, 46 and 8. The venturi and throttle device, either with or without the solenoid, is preferably balanced, that is, itis unaffected, when moving or at rest, by the flow of mixture, andis sensitive to. slight increases or decreases'oi the force controlling its movement. The de vice reaches its position of equilibrium in each instance without hunting, owing to. the substantial force tending to bring it to such position whenever the condition of equilibrium has been disturbed from any cause. Hunting may be avoided by having the algebraic increase of mechanical force (spring force plus weight of moving parts) with downwardly movingcore, greater than the corresponding algebraic increase ofmagnetic pull with downward movement of the core llllOllQllOllh the working part of thestroke. Furthermore, by having the magnetic circuit complete except for small air gapsbetween i1) and flange and between core and plug, the olenoid has a high magnetic eiliciency, which neans compactness and economy of construction and operation.

The solenoid has preferably two windings :31, 32, as above noted. These are respectively shunt and series windings. A preferred type of wiring is shown in Fig. 6, wherein the shunt winding 31 is connected to the terminals of the engine-driven generator G and the series winding 32 is connected to carry generator current, the-'scrieswinding opposing the shunt winding and weakening the solenoid pull when the load increases- This makes it possible to have a substantially flat voltage characteristic. Or, the voltage may be' caused to increase with increase of load, or any other desired characteristic of similar nature may be obtained by varying the ratio or! series and shunt turns.

i The automatic choke device shown at the top of the solenoid in Figs. 1 and 2 maybe dispensed with if desired. This device comprises a solenoid having a magnetic shell 69,, bobbin 71, winding 7 3, and movable core'75. The lower end or the core 75 acts as the upper surface of the air inlet passage 79. The soleno'id winding 73 is preferably connectedacross the generator mains, as indicated in 6. The winding 78 is thus ale-energized when the generatorG is being started. This means that during the starting of the engine the core 7 5 is in its lowermost position, shown in dotted lines in Fig. 1, thereby shutting off. part of the air supply and givii'ig-an increased suction during starting. In other words, this construction ailords an automatic chokedur ing starting.

It -"desired, a conduit 8]. may extend from the crank-case (not shown) of the engine (not shown) into the air inlet 2. The suetion in the air inlet induces a suction in the conduit 81, thereby providing what may be termed an oil breather to draw oil and the other vapors from the crank-case. In the present instance the vapors are drawn into the engine, where the lubrication afforded by the oil may be of value. 'lhisoperation serves to ridthe room in which the apparatus is located, 01 the odors of such vapors.

I -he level of the top of the overflow pipe 66 (Fig. 3) determines thejh ad on the gasoline feed. This level is preferably a little below the level of the 17,-so that suction is required at the jet to" bring fuel from the cluiniber 25 to the jet.

i I" desired, steam (it available) may be a iLl'Gtl through the conduit 93, together with air through the conduit 95, into a passage 97 controlled by an adjustable needle valve 99, so that steam may be supplied to the air passage 7 9 along with the air that enters this passage through the inlet tube. It iotod that such steam is subject to the chok- 1n cll'ect of the core 75. 7

From the above it will be seen that in the apparatus of the present invention the sev eral objects above need are attained and other advantageous results secured.-

As various possible en'ibodiments might be made of the above invention and as various changes might be made in the embodiment above set forth without departing from the spirit or scope of this invention, it is to be understood that all matter herein set forth a spring adapted to engage the stops to op pose the movement of the solenoid core.

2. Iniapparatus of the class described, in combination, a movable venturi, and means for operating said'venturi, said means comprising a solenoid having a movable element, a series of stops, and resilient means associated with said movable element adapted to engage said stops successively to oppose the movement of the movable element of the solenoid.

3. In apparatus of the class described, in combination, a needle valve, an inlet air passage, a fixed member apertured to receive fuel from a source of supply through the needle valve and said fixed member being adapted to eject the fuel into said air passage to form a combustible mixture with said air, a vertically movable member having a port to permit flow of said combustible mixture of fuel and air from said air passage, a solenoid for operating said movable member, and a spring associated with said solenoid abutting successive stops tooiferincreasing resistance to movement of said movable member.

l. In apparatus of the class described, in combination, a valve adapted to control a fuel supply, an inlet air passage, a fixed mem- 7 her apertured to receive fuel from a source of supply through said valve, said fixed member being adapted to eject said fuel into the air passage to form a combustible mixture, a movable member adapted to control the flow of said combustible mixture from said air passage, and a solenoid for operating said movable member, said solenoid having means associated therewith adapted to offer increasing resistance to the movement of said second member as the solenoid moves said second member to close.

5. In apparatus of the class described, in combination, a movable venturi and throttle member, and means for operating the same, said means comprising a solenoid having a core adapted to move said member and means associated with said solenoid core adapted to increasingly oppose the movement of the solenoid core as said core becomes incrcasingly efiective in its movement of said member.

6. In apparatus of the class described, in combination, a movable throttle member, and means for operating the same, saic means comprising a solenoid having a core adapted to move said member, and means associated with the solenoid adapted to maintain the throttle member in equilibrium at different points in its range of movement and to control said movement in a predetermined manner, said last-named means comprising a magnetic shell on the solenoid, a rib on said shell, a flange on said core cooperating with said rib, a spring adapted to oppose the movement of the solenoid core and a series of stops abutted by said spring. 7

7. In apparatus of the class described, in combination, a movable venturi and throttle member, and means for operating the same, said means comprising a solenoid having a core adapted to move said member, and means associated with the solenoid adapted to maintain the throttle in equilibrium at different points in its range of movement and to control said movement in a predetermined manner, said last-named means comprising a magnetic rib in the magnetic circuit of said solenoid, means on said core movably cooperating with said rib, and means for increasingly resisting the movement of the solenoid core as said movement increases.

8. In apparatus of the class described, in combination, a member adapted to receive fuel from a source of supply, having a pas sage for fuel therein, a throttle member surrounding said first-named member, an air inlet for admitting air to the space between said members, said throttle member controlling the fiow of fuel mixture from said space to a discharge conduit, means whereby air passing through the throttle member draws fuel from said passage, the parts being proportioned to give proper mixture in the several positions of said throttle member and means for automatically operating said throttle member comprising a solenoid having a core movable with said throttle member, a magnetic shell for the solenoid, a rib extending from said shell and a flange on said core registering with said rib when the throttle is in its open position. 7

In testimony whereof, I have signed my name to this specification this 28th day of March, 1922.

. HARVEY S. PARDEE. 

